Seeing I missed the Halloween post last week, I thought I’d make this one a little on the topic. I generally like spiders, they are a great way of controlling the local insect population. Although vacuuming the ceiling every couple of weeks can be annoying!
Spiders are related to insects and crayfish, they are all arthropods. This means they have jointed legs and a shell on the outside known as the exo-skeleton. It protects them but it doesn’t grow, when they get bigger they need to push it off and grow a new one. We find lots of daddy-long-legs skins around where they have moulted.
Spiders have two body parts, the abdomen and head. They have 8 legs, 4 on each side, coming off the head segment.
Spiders can have up to 8 eyes! You can see here there are two big ones in the middle, two medium ones at the back and four little ones across the front. This is why it is so hard to catch a spider – they can see you coming 🙂 This spider is a jumping spider, they hunt prey by jumping on them. So they need all the eyes to help them find their food and then judge exactly where they are.
Now for the icky part – the mouth. A spider’s mouth is made out of the same parts as their legs. It has two pairs of mouth parts for holding food and bringing it to the mouth. It cannot chew or eat anything solid, just suck the juices out of its prey. The only ‘teeth’ spiders have are their fangs which inject poison, this isn’t just to kill but breaks down the prey for them to suck. These fangs are on a Sydney Funnel-Web, which is deadly. Many spiders are not dangerous for humans because their fangs are not big enough to hurt us, but all spiders should always be left alone just in case.
- All spiders can make silk, some make webs for catching insects like the one shown above. In this classic web there are two different types of silk. The long lines going out are strong to support the web and for the spider to walk on. The lines going around are sticky to catch insects that fly past.
- When spiders want to get around they trail a long line of silk behind them, it acts as a parachute or the tail of a kite and lets the wind carry them.
- A red-back spider in Cairns ate a snake she caught in her web. There are great photos at the link.
- There is a vegetarian spider. It is a type of jumping spider but has switched to eating protein rich nodules on plants. They seem to be fairly social rather than territorial, with many on the same plant and even living in the same nest.
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